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1.
准确测量LD/LED的P-I曲线,对于LD/LED的科学研究、生产制造及实际使用均具有很大意义.介绍了一种简易的LD/LEDP-I曲线测试平台,该测试平台可间接连续地测出LD/LED的P-I曲线,并可以读出LD/LED在不同电流下的功率经光电转换后的电压值及LD的阈值电流.采用ICL8038芯片产生锯齿波,经V/I芯片AD694转换为0~20mA的锯齿波电流来驱动LD/LED.测试平台电路简单、易于实现、成本低,可操作性较强,可以很好地满足学生自己动手进行LD/LED特性参数相关实验的要求.结果表明,系统的可靠性较好.  相似文献   

2.
3.飞利浦32TA2800液晶彩电伴音电路分析(1)音频处理电路全功能超级芯片U4101(MST96889LD)内部集成了音频解调和处理电路,具有:音量、平衡、低音、高音、静音、均衡器和环绕声等功能。音频处理电路的工作过程如下:TV单声道音频信号加到U4101的(80)脚,TV第二伴音中频信号加到U4101的  相似文献   

3.
为了旧彩电升级、播放VCD、LD高清晰的画面,笔者给松下2185型机加装了AV输入功能(AV板电路如图1所示)。由于该机与松下2186机电路相近,故改装时参考了松下2186机的电路。因本机底板是带电的热机芯,音频功放是电子直流音量控制,因此选用一  相似文献   

4.
③自动功率控制(APC)电路。激光头都附设自动功率控制电路,并用APC表示,它的主要功能是保证激光头输出稳定的激光辐射功率。该激光头附设APC电路,如图6所示。该电路主要包括:传感头电路、两级同相放大器IC1A和IC1B、π型滤波器及LD模块电路等。  相似文献   

5.
③自动功率控制(APC)电路。激光头都附设自动功率控制电路,并用APC表示,它的主要功能是保证激光头输出稳定的激光辐射功率。该激光头附设APC电路,如图6所示。该电路主要包括:传感头电路、两级同相放大器IC1A和IC1B、π型滤波器及LD模块电路等。  相似文献   

6.
针对目前生产的低压差线性稳压器(LD0)最低输出电压均大于1V的问题,设计一种由通用元器件构成输出电压低于1V的LDO,电路由基准电压源、误差放大器、PNP型功率管和驱动电路构成。详细分析了电路设计原理,在给出实测数据的同时,还利用PSpice软件进行了电路仿真,证明所设计的LDO电路符合规定指标。  相似文献   

7.
交流电压真有效值的测量   总被引:4,自引:0,他引:4  
介绍有效值变换器AD736、A/D转换器 710 6和液晶显示器LD—B70 15A组成的交流电压真有效值测量电路  相似文献   

8.
(3)卡拉OK电路卡拉OK电路如图73所示(以松下LX—K770为例)。该电路的音频信号处理电路的音源有四种:①录制在碟片上数字伴音信号;②录制在碟片的模拟伴音信号;③从音频输入接送来的音频信号;④从话筒输入的话筒信号。这些信号可以进行开关控制和各种处理,从而实现了各个功能和不同的效果。从该电路来看IC4001为数字音频解调电路,LD数字伴音和CD碟  相似文献   

9.
电力线通信信道背景噪声建模研究   总被引:4,自引:0,他引:4  
噪声干扰是影响电力线通信可靠性的最主要因素之一.分析了电力线通信信道背景噪声,搭建了背景噪声测量电路,建立了实测背景噪声的AR模型,分别用奇异值分解法和Levinson-Durbin (LD)递推法计算其AR模型参数,并进行仿真比较分析.结果表明:利用奇异值分解法所求参数和利用LD递推法所求参数都是可行的,奇异值分解法所得参数模型较为复杂,但极为精确,适合电力线通信信道背景噪声的离线计算和分析;LD递推法所得参数模型极为简单,但丧失了较大精度,适合电力线通信信道背景噪声的在线快速生成.  相似文献   

10.
介绍了一种基于LD7670芯片的反激式DC/DC电源模块。首先分析了LD7670的特性,介绍了电源电路的工作原理,并进行了实际参数的计算、器件的选取,最后给出了该电源的测试结果。结果表明,利用该芯片设计的电源模块,不但具有体积小、效率高、纹波小、输出电压稳定等优点,而且具有输入电压变化范围宽、动态响应快、电压调整率和负载调整率高,性能可靠,具有一定的应用价值。  相似文献   

11.
It is shown that semiconductor lasers utilizing intersubband transitions in quantum boxes, so-called intersubband quantum-box (IQB) lasers, can have significantly lower threshold current densities and operating voltages than quantum cascade (QC) lasers. In order to achieve this result, an enhancement factor of about 20 in the LO-phonon-assisted electron relaxation time is necessary. The increased gain for the radiative stage in an IQB laser eliminates the need for a multiradiative-stage structure (typically 25 stages in QC lasers). In turn, the electron injector and Bragg mirror regions on either side of the active region can be separately optimized. Due to their inherently lower input power requirements, IQB lasers operating in the mid-IR wavelength range should be capable of higher average-output powers than QC lasers at all temperatures. Furthermore, continuous-wave (CW) operation at room temperature with high wallplug efficiency becomes possible  相似文献   

12.
采用新型谐振式软开关技术,成功地研制出激励高功率轴快流CO2激光器的零电流谐振式软开关电源。该电源工作在25 kHz的开关频率下,主电路采用半桥式谐振变换方式,电源处于软开关工作方式,IGBT功率管为零电流开通和关断。该电源输出电流5~120 mA连续可调,功率管低损耗工作,无需镇流电阻,实现了6支CO2激光放电管的并联起辉和稳定工作。  相似文献   

13.
Cryogenic cooling of solid-state lasers has a number of important benefits, including the near vanishing of optical distortion in high average power lasers, as well as enhanced spectroscopic and lasing properties. These benefits are just beginning to be exploited to produce compact high average power lasers whose output is scalable, near diffraction limited, and whose efficiencies will exceed those of modern bulk solid-state lasers. In this paper, we review the history of cryogenically cooled solid-state lasers and the benefits of cryogenic cooling, including optical and laser properties and thermal and thermooptic properties; examine cryogenic amplifiers and cooling methods, including a straight-through propagation thin-disk configuration that does not perform well at room temperature, and summarize the experimental performance demonstrated to date. As a specific example, we examine the spectroscopic and lasing properties of Yb:YAG and show that compact high efficiency and high average power, near diffraction limited lasers (>100 kW) can be realized in the near future using presently available technology.  相似文献   

14.
The influence of strain on lasing performances of Al-free strained-layer Ga(In)As(P)-GaInAsP-GaInP quantum-well lasers is investigated for the first time over a large emission range of 0.78<λ<1.1 μm. GaAsP and InGaAs are used for tensile and compressive-strained quantum-well layers, respectively, while GaAs and GaInAsP lattice-matched to GaAs are applied for unstrained quantum wells. The laser structures were prepared by using gas-source molecular beam epitaxy, and broad-area and ridge waveguide Fabry-Perot laser diodes were fabricated. This study shows that applying both tensile and compressive strains in the quantum well reduces threshold current density for the Al-free strained-layer quantum-well lasers. However, it was found that the lattice relaxation set a limitation of maximum compressive strain (i.e., maximum lasing wavelength) for the compressive strained InGaAs lasers while the carrier confinement determined the acceptable maximum tensile strain (i.e., minimum lasing wavelength) and lasing performances for the tensile strained GaAsP lasers. Threshold current density as low as 164 A/cm2 has been obtained for 1.4% compressive-strained InGaAs-GaInAsP-GaInP lasers having a 12-nm thick quantum well. However, excellent characteristics, such as low threshold current, high efficiency low internal loss, and high output power, have been achieved for the Al-free strained-layer quantum-well lasers  相似文献   

15.
High-output-power operation of 1.55-μm-wavelength distributed-feedback (DFB) lasers with a novel mass-transport grating (MTG) structure which is composed of InAsP buried with InP are reported. To improve high output power characteristics, we have investigated the influence of the width of the active layer on the light output power and the spectral linewidth at high injection current. It is confirmed that the increase of the active layer width is effective to realize high output power and to reduce the linewidth power product. The fabricated lasers show high single-longitudinal-mode output power of 180 mW, which is the highest value reported for 1.55-μm DFB lasers. They also exhibit narrow spectral linewidths less than 0.3 MHz and low noise characteristics of -159 dB/Hz. Moreover, we have obtained the mean time to failure of longer than 105 h with a lifetime test over 200 h at 50°C  相似文献   

16.
廖丹  杨建强 《电子测量技术》2009,32(12):102-105,109
为实现四频差动激光陀螺的稳频控制等功能,需要快速精确测量陀螺的光强、电流和温度信号。使用单片6通道、16位AD转换芯片AD7656,与高性能DSP芯片TMS320F2812设计而成的检测系统,解决了XINTF接口数据传输等问题,并采用均值滤波方法,能有效、实时、精确地采样四频差动激光陀螺各种信号,大大降低陀螺测量控制电路的功率和体积。在10kHz的采样率下,系统测量信号精度可达10^-4量级。电路能够长期稳定工作,满足对陀螺信号的测量要求,达到预期目标。  相似文献   

17.
本文描述一种适用于测试脉冲功率中高平均功率元件性能和寿命的试验台,其重复频率可达100Hz。文中分析了C-L-C谐振充电回路。测得CS开关两种电极材料的磨损特性。RRTS可以用来测试和执行认可,以及评估重复频率开关、脉冲电容器,脉冲变压器等性能和寿命,亦可作为准分子激光及医用激光的高重复频率供电电源之用。  相似文献   

18.
Recent progress in semiconductor quantum-dot (QD) lasers approaches qualitatively new levels, when dramatic progress in the development of the active medium already motivates search for new concepts in device and system designs. QDs, which represent coherent inclusions of narrower bandgap semiconductor in a wider gap semiconductor matrix, offer a possibility to extend the wavelength range of heterostructure lasers on GaAs substrates to 1.3 /spl mu/m and beyond and create devices with dramatically improved performance, as compared to commercial lasers on InP substrates. Low-threshold current density (100 A/cm/sup 2/), very high characteristic temperature (170 K up to 65/spl deg/C), and high differential efficiency (85%) are realized in the same device. The possibility to stack QDs (e.g., tenfold) without an increase in the threshold current density and any degradation of the other device parameters allow realization of high modal gain devices suitable for applications in 1.3-/spl mu/m short-cavity transmitters and vertical-cavity surface-emitting lasers (VCSELs). The 1.3-/spl mu/m QD GaAs VCSELs operating at 1.2-mW continuous-wave output power at 25/spl deg/C are realized, and long operation lifetime is manifested. Evolution of GaAs-based 1.3-/spl mu/m lasers offers a unique opportunity for telecom devices and systems. Single-epitaxy VCSEL vertical integration with intracavity electrooptic modulators for lasing wavelength adjustment and/or ultrahigh-frequency wavelength modulation is possible. Arrays of wavelength-tunable VCSELs and wavelength-tunable resonant-cavity photodetectors may result in a new generation of "intelligent" cost-efficient systems for ultrafast data links in telecom.  相似文献   

19.
ABSTRACT

Dependence of both acceptance bandwidth and frequency conversion efficiency on the linear periodicity fluctuation in domain-inverted KTP crystals was investigated. The study was mainly focused on three main emission wavelength bands of current commercially available high power optical fiber lasers. That to use these artificially introduced domain periodicity fluctuations as the potential means to match the nonlinear crystal's acceptance bandwidth to a high power fiber laser's emission linewidth is believed effective in maximizing the nonlinear frequency conversion efficiency as much as possible.  相似文献   

20.
We conduct a theoretical analysis of the design, fabrication, and performance measurement of high-power and high-brightness strained quantum-well lasers emitting at 0.98 /spl mu/m. The material system of interest consists of an Al-free InGaAs-InGaAsP active region and AlGaAs cladding layers. Some key parameters of the laser structure are theoretically analyzed, and their effects on the laser performance are discussed. The laser material is grown by metal-organic chemical vapor deposition and demonstrates high quality with low-threshold current density, high internal quantum efficiency, and extremely low internal loss. High-performance broad-area multimode and ridge-waveguide single-mode laser devices are fabricated. For 100-/spl mu/m-wide stripe lasers having a cavity length of 800 /spl mu/m, a high slope efficiency of 1.08 W-A, a low vertical beam divergence of 34/spl deg/, a high output power of over 4.45 W, and a very high characteristic temperature coefficient of 250 K were achieved. Lifetime tests performed at 1.2-1.3 W (12-13 mW//spl mu/m) demonstrates reliable performance. For 4-/spl mu/m-wide ridge waveguide single-mode laser devices, a maximum output power of 394 mW and fundamental mode power up to 200 mW with slope efficiency of 0.91 mW//spl mu/m are obtained.  相似文献   

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